Products with a patterned light-transmissive portion

ABSTRACT

A panel with an optically transmissive portion includes a group of holes drilled from one surface to another surface and filled with an optically transmissive material. The group of holes forms a pattern. The holes on a first surface form a smooth and continuous appearance to the naked eye. The holes on the other, second surface are sized so that a light source directed to the second surface illuminates the pattern to be visible to a viewer viewing the first surface. The panel may form a portion of a housing that houses the light source.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 11/742,862,filed May 1, 2007, which claims the benefit of U.S. ProvisionalApplication No. 60/810,380, filed Jun. 2, 2006, each of which isincorporated herein in its entirety by reference.

FIELD OF THE DISCLOSURE

The disclosure herein relates to products with a patternedlight-transmissive portion, such as a panel and/or housing with apatterned light-transmissive portion.

BACKGROUND

Projecting a light through a housing to provide information iscommonplace. Examples include but are not limited to computer keyboardsthat include indication lights for functions such as “Caps Lock” or “NumLock”; computer monitors that include an “on/off” light automobiles thatinclude lights to indicate whether heated seats are on or off, orwhether an air bag is on or off; televisions with indicator lights, anda whole host of other consumer electronics.

A common way to provide for such lighting is to provide a projectinglight that is visible when the light is off and brightly lit to indicatewhen the light is on. A collection of lights, or holes for lights, maybe disruptive to the objectives of an industrial designer.

SUMMARY

Disclosed are methods for forming a display in a relatively thinsubstrate or panel with a material that permits the transmission oflight through microholes filled with a transparent filler material andproducts that are made by such methods.

One apparatus described herein includes a panel having a first externalsurface and an opposite, second external surface, wherein a material ofthe panel is non-transmissive to light, a pattern of microscopic holesdrilled through at least a portion of the panel, wherein openings of themicroscopic holes are sized such that light applied to the secondexternal surface illuminates the pattern on the first external surfaceand the first external surface forms a continuous panel surface to thenaked eye when light is not applied to the second external surface, anda light transmissive material filling the microscopic holes.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawingswherein like reference numerals refer to like parts throughout theseveral views, and wherein:

FIG. 1 is a schematic representation of the sequence of method of thepresent disclosure;

FIG. 2 is a schematic representation of a conically-shaped via or holegeometry;

FIG. 3 are SEM micrographs taken of a panel having conically-shaped viasshowing the first or back side of a panel with the larger via opening;

FIG. 4 are SEM micrographs of vias showing the second or visible side ofthe panel having the smaller opening of the conical via;

FIG. 5. is a SEM micrograph of the visible side of the panel having thesmaller opening of the exemplary vias with the filler material in thevias;

FIG. 6. is an optical micrograph of the visible side of the panel havingthe exemplary vias filled with the filler material and havingbacklighting to show transmission of light through the conical vias asviewed from the visible side of the panel;

FIG. 7 is an enlarged optical micrograph of the visible side of thepanel shown in FIG. 6;

FIG. 8 is a SEM micrograph cross-section of several vias filled with thefiller material;

FIG. 9 is an enlarged SEM micrograph cross-section of a filled conicalvia shown in FIG. 8;

FIG. 10 is a schematic representation of an alternate configuration ofthe filler material on the visible side of the panel;

FIG. 11 is a SEM micrograph of the alternate filler materialconfiguration shown in FIG. 10;

FIG. 12 is an optical micrograph of the alternate filler materialconfiguration shown in FIG. 11;

FIG. 13 is a schematic representation of an alternate configuration ofthe filler material on the visible side of the panel;

FIG. 14 is a SEM micrograph of the alternate filler materialconfiguration shown in FIG. 12;

FIG. 15 is an optical micrograph of the alternate filler materialconfiguration shown in FIG. 14;

FIG. 16 is a schematic representation of an alternate configuration ofthe filler material on the visible side of the panel;

FIG. 17 is a SEM micrograph of the alternate filler materialconfiguration shown in FIG. 16;

FIG. 18 is an optical micrograph of the alternate filler materialconfiguration shown in FIG. 17; and

FIG. 19 is a schematic representation of a housing utilizing a lighttransmissive panel including filled vias.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Referring to FIGS. 1-18, methods for filling at least one via with alight transmissive material are shown and described below. FIG. 19illustrates a product resulting from one of the methods. The disclosureutilizes via drilling techniques to create a micro via that is thenfilled with a light transmissive material. Via drilling is known in theunrelated field of electronics manufacturing. Vias are created inmulti-layered interconnected substrates and lined with a conductor, suchas copper, to permit an electrical connection between different layersin a circuit.

A method 10 and steps for filling a via with light transmissive materialare illustrated in FIG. 1. A panel or substrate 12 is provided. Panel 12as shown is a relatively thin continuous sheet of material. Panel 12includes a first or back side 14 and an opposing second or front side 18defining a panel thickness 20. Front side 18 is relatively smooth andsubstantially unbroken to the naked eye. Panel 12 may be made fromanodized aluminum or other materials known to those skilled in the art.

The method 10 includes drilling one or a plurality of micro-vias orholes 30 through the panel 12. As shown in FIGS. 2-4, 8 and 9, in oneaspect of the method the vias 30 are conical-shaped having sidewalls 34and a first opening 40 in panel first side 14 and an opposing secondopening 44 on panel side 18. First via opening 40 is larger in diameterthan second via opening 44. In one aspect, first via opening 40 isapproximately 90-100 micrometers (μm) in diameter, and second viaopening 44 is approximately 30-40 micrometers (μm) in diameter. It isunderstood that larger or smaller conical openings and other via shapesand configurations may be used.

The vias shown are drilled or machined out of the panel using a laser24, such as a diode-pumped solid-state pulsed laser, in a circular orspiral pattern. It has been shown that a Nd:YAG 355 nm spot 22 with apulse repetition rate of 30 kHz and ˜60 nanosecond pulse width is usefulin machining out the preferred conical-shaped vias 30. Drilling of theexemplary vias 30 is accomplished from back side 14 through panel 12toward the front side 18. Other types of lasers with differentcharacteristics and other machining processes from drilling vias knownto those skilled in the art may be used to suit the particularapplication.

The method 10 optionally includes the step 46 of cleaning the drilledvias 30 to remove any debris or deposits formed during the machiningprocess. It has been shown that a CO₂ snow jet cleaning and isopropylare effective in cleaning the vias. Other via cleaning techniques knownby those skilled in the art may also be used. For example, ultrasoniccleaning using, for example, ultrasonic baths may be used. Also, theapplication of high-pressure air, like the snow jet, may be made from asource movably located in a similar manner to the drill 24 to clean thevias.

As shown in FIGS. 1 and 5-9, the method 10 includes applying a fillermaterial coating 50 into the vias 30. The filler material 50 may be avisible light transmissive material. As illustrated, filler material 50is an optically transparent ultraviolet (UV)-curable, acrylate polymerthat is in a liquid phase at the time of application to panel 12. Otherplastics or polymers with light transmissive properties may also beused. The exemplary UV curable filler material is substantially clearwhen cured. As best seen in FIG. 1, the filler material 50 can beapplied to the panel second side 18 over the top of the second,optionally smaller openings 44, of vias 30. It has been observed thatthrough the relatively low viscosity of the exemplary liquid phasefiller material 50, the geometry of the conically-shaped vias 30 and theforces of gravity, the filler material 50 flows into and through thevias 30 from the second side 18 to the first side 14, effectivelyfilling the vias 30 as best shown in FIGS. 1, 8 and 9. Excess fillermaterial 50 may propagate on panel 12 second side 18 (shown as 66) andfirst side 14 (shown as 62) as best seen in FIG. 1. The filler material50 as shown is applied with a syringe-type device 54. Other fillermaterial 50 application devices and techniques known by those skilled inthe art may be used. Examples include ink jet techniques and padprinting techniques.

In an alternate aspect, filler material 50 may be applied to back side14 so the filler material 50 flows through via 30 from back side 14toward front side 18 in a similar manner as described.

When a curable filter material is used, method 10 may include the step76 of curing the exemplary liquid phase silica-based filler material 50by exposing the filler 50 to UV light. Exposure to UV light 76 initiatesfree-radical polymerization of the silicate filler material 50 insideand through vias 30. In one method of applying the UV light, the UVlight is applied to back side 14 and via 30 (i.e., the large openings40) to promote curing of filler material 50 in vias 30. When cured, theexemplary filler material 50 is optically transparent permitting passageof visible light through the filler 50 and panel 12 through vias 30.

Method 10 includes the step 82 of removing any excess or uncured fillermaterial deposits 66 from the panel visible, front side 18 as shown inFIG. 1. For example, filler excess deposits 66 may be removed from frontside 18 through a simple isopropanol wipe, leaving a visibly smooth andclean surface. Other methods and techniques for removing excess deposits66 may be used.

Method 10 may optionally include the step 90 of exposing the fillermaterial 50 in vias 30 adjacent to the visible panel side 18 after thestep of removing excess deposits 66 to assist curing of the fillermaterial 50 throughout vias 30. Referring to FIG. 9, the filler material50 most adjacent to the panel visible surface 18 may be slightly belowfront side 18 forming a recess 94 between the filler 50 and front side18.

As best seen in FIGS. 10 -18, treatment of the filler material directlyadjacent to the visible panel surface 18 may be varied to change orenhance the visual appearance of the filler material 40 and visiblelight passing therethrough for a user. In an alternate aspect of method10, cured excess filler deposits 66 may take a convex shape or form asopposed to being recessed into vias 30 as shown in FIG. 9. For example,FIGS. 10-12 and FIGS. 13-15 illustrate two such convex forms for thecured excess filler deposits 66. In FIGS. 10-12, the convex shapeextends beyond and surrounds the second via opening 44. In FIGS. 13-15,the convex shape is approximately limited to the area of the second viaopening 44. Through different shapes or configurations, the visiblelight passing through the filler material 50 may be altered to produce adifferent visual appearance or effect to the user similar to alteringthe shape or configuration of a lens. As another example, FIGS. 16-18illustrate, instead of a concave or convex shape, a flush fill, that is,an embodiment where the filler material 50 is flush with the surface ofthe second, or front, side 18.

The cured filler material 50 and front side 18 from the method 10results in protected vias 30 capable of transmitting light through panel12. The use of vias and an optically transparent filler materialproduces a smooth and continuous panel surface to the naked eye that iscapable of displaying controlled images through the vias from interiorillumination, as shown in FIG. 19. FIG. 19 illustrates a panel 12including a back light 70, which may be an LED, fluorescent orincandescent light, or other lighting devices. Panel 12 may be a sectioninserted into a housing or may be an integral section of the housing 72as shown in FIG. 19.

The resultant panel 12 can be used in all manner of applicationsincluding hand-held electronic devices, for example, MP3 players,computers, cellular phones, DVD players and the like. The disclosedmethod and resultant panel is applicable in virtually all applicationswhere a visually continuous and uninterrupted panel surface is desiredhaving the capability to produce illuminated messages, images or otherperceptible characteristics for the user.

While the method has been described in connection with certainembodiments, it is to be understood that the method is not to be limitedto the disclosed embodiments but, on the contrary, is intended to covervarious modifications and equivalent steps and arrangements includedwithin the scope of the invention and any appended claims.

What is claimed is:
 1. An apparatus, comprising: a panel having a firstexternal surface and an opposite, second external surface, wherein amaterial of the panel is non-transmissive to light; a pattern ofmicroscopic holes drilled through at least a portion of the panel,wherein openings of the microscopic holes are sized such that lightapplied to the second external surface illuminates the pattern on thefirst external surface and the first external surface forms a continuouspanel surface to the naked eye when light is not applied to the secondexternal surface; and a light transmissive material filling themicroscopic holes.
 2. The apparatus of claim 1 wherein the panel formsportion of a housing, the apparatus further comprising: a light sourcelocated within the housing and located so as to transmit light intoopenings of the microscopic holes opposite from the first externalsurface.
 3. The apparatus of claim 1 wherein each of the microscopicholes is conically-shaped with a smaller opening at the first externalsurface than at the second external surface.
 4. The apparatus of claim 3wherein a diameter of each of the microscopic holes at the firstexternal surface is about 30 μm.
 5. The apparatus of claim 3 wherein adiameter of each of the microscopic holes at the second external surfaceis about 50-90 μm.
 6. The apparatus of claim 1 wherein the lighttransmissive material is a cured polymer.
 7. The apparatus of claim 1wherein each of the microscopic holes is substantially conical, adiameter of a smaller end of each conical hole is between about 10 and50 μm and a diameter of a larger end of each conical hole is betweenabout 60 and 200 μm.
 8. The apparatus of claim 1 wherein the panelcomprises anodized aluminum.
 9. The apparatus of claim 1 wherein thepattern comprises one of a message or an image.